Method For Analytically Determining SLS Bed Temperatures

ABSTRACT

A method for determining a bed temperature setpoint for use with a powder in a selective laser sintering machine is disclosed. The method includes the step of providing a powder comprising a polymer for use in a selective laser sintering machine. The method further includes the step of determining a ratio of a liquid portion of the powder to a solid portion of the powder as a function of temperature within a temperature range. A bed temperature setpoint is selected in the temperature range corresponding to a desired ratio of the liquid portion of the powder to the solid portion of the powder. A temperature of a bed of a selective laser sintering machine is set to the selected bed temperature setpoint, and a part is built from the powder using the selective laser sintering machine.

TECHNICAL FIELD

The present disclosure relates to a system and method for processingpolymer resins. More specifically, the present disclosure relates to asystem and method for determining a bed temperature setpoint for aselective laser sintering (SLS) machine for use with a polymer powder,including polyaryletherketones (“PAEK”).

BACKGROUND

Selective laser sintering (“SLS”) is an additive manufacturing techniquethat uses electromagnetic radiation, for example from a laser, to fusesmall particles of plastic, metal (direct metal laser sintering),ceramic, or glass powders into a mass having a desired three dimensionalshape. The laser selectively fuses powdered material by scanningcross-sections generated from a three dimensional digital description ofthe part on the surface of bed having a layer of the powdered materialdisposed thereon. After a cross-section is scanned, the bed is loweredby one layer thickness, a new layer of powdered material is disposed onthe bed, and the bed is rescanned by the laser. This process is repeateduntil the build is completed.

Prior to scanning, an SLS machine typically preheats the powder materialdisposed on the bed to a temperature proximate to a melting point of thepowder. Preheating is typically accomplished by heating the actual bed,which transfers energy to the powder in the form of heat via thermalconduction. Preheating the powder makes it easier for the laser to raisethe temperature of powder to a fusing point.

When working with certain material in the SLS process, for examplepolymer powders, the bed temperature is set to a temperature specific tothe polymer resin in use. This specified temperature is typicallyproximate to the melting point of the polymer resin. The laser causesfusion of the powder in locations specified by the build input. Laserenergy exposure is typically selected based on the polymer in use and isbetween the amount required to fuse the resin and the amount that willcause degradation. Preheating of the material inhibits unwanteddistortions in formed parts during cooling.

After the layer-wise process is completed, the formed object(s) isdisposed in a volume of unfused powder, referred to as a cake. Theformed object(s) is extracted from the cake. The powder from the cakethat is not fused into the built part can be recovered, sieved, and usedin a subsequent SLS build.

Polyaryletherketones (“PAEK”) are of interest in the SLS process becauseparts that have been sintered from PAEK powder are characterized by alow flammability, a good biocompatibility, and a high resistance againsthydrolysis and radiation. The thermal resistance at elevatedtemperatures as well as the chemical resistance distinguishes PAEKpowders from ordinary plastic powders. A PAEK polymer powder may be apowder from the group of polyetheretherketone (“PEEK”), polyetherketoneketone (“PEKK”), polyetherketone (“PEK”), polyetheretherketoneketone(“PEEKK”), or polyetherketoneetherketoneketone (“PEKEKK”).

The bed temperature setpoint may be determined, for example, byreferring to a temperature setpoint published by a vendor of the powder.In such circumstances, the operator sets the SLS bed temperature to thesetpoint specified by the vendor and commences the SLS build processwhen the bed has achieved the setpoint temperature.

A disadvantage of relying on a bed temperature setpoint specified by avendor is that the melting point of the powder may vary betweendifferent lots of powder. This is true even if between different lots ofthe same type of powder. As a result, the temperature setpoint specifiedby the vendor may be incorrect for the actual lot of powder being usedin the build.

Another disadvantage of relying on a bed temperature setpoint specifiedby a vendor is that the vendor provides a setpoint for a lot of purepowder. Typically, a vendor does not provide a bed temperature setpointfor a lot subsequently prepared by the operator by, for example,combining two or more types of powder, for example two differentpolymers. Similarly, a vendor typically does not provide a bedtemperature setpoint for a powder having one or more fillers.

Another disadvantage of relying on a bed temperature setpoint specifiedby a vendor is that a melting point of unused powders versus a meltingpoint for recycled powders can vary dramatically. As a result, it isnecessary to use different bed temperature setpoints depending onwhether an SLS powder lot consists of unused powder, first recyclepowder, second recycle powder, or some combination thereof. For example,as disclosed in U.S. application Ser. No. 13/705,332 to DeFelice et al.,the difference between the bed temperature setpoint for unused PEKKpowder and first recycle PEKK powder is fifteen degrees Celsius. The'332 application to DeFelice is hereby incorporated by reference.

Another disadvantage of relying on a bed temperature setpoint specifiedby a vendor is that certain polymer powders, for example PEKK, arecopolymers. A copolymer comprises two (or more) monomeric species. Forexample, PEKK is a copolymer (AB type EKK/EKK). In lots of suchcopolymers, the ratio of a first species compared to a second speciesmay be varied to achieve, for example, blends having different ratios. Aproblem with such copolymers is that the temperature at which fusinginitiates may vary based on the ratio of the first species relative tothe second species, thus making it difficult to select a correct bedtemperature setpoint.

As a result of these disadvantages associated with bed temperaturesetpoints specified by a vendor, incorrect bed temperature setpoints areoften used in SLS runs. An incorrect bed temperature may results inserious structural problems in the part formed during the SLS procedure.For example, if the bed temperature setpoint is too low, the built partmay become distorted relative to the desired three-dimensional shape. Ifthis happens, the built part may be discarded, or it may requireadditional man hours to further shape the part so that it conforms tothe desired three-dimensional shape, to the extent reshaping isfeasible.

If, on the other hand, the bed temperature setpoint is too high, thepowder may began to melt or fuse prior to being sintered in the layerwise fashion. This can result in a built part with substantialstructural flaws, and, if the bed temperature setpoint is above acertain temperature setpoint it may prevent formation of athree-dimensional part from during the SLS process because successivelayers will not fuse together.

It is known to overcome the problems associated with reliance on a bedtemperature setpoint specified by a vendor by observing properties of apowder in an SLS machine during a warmup cycle. In this observationmethod, a layer of powder is disposed on a bed at a temperature wellbelow the melting point of the disposed powder, for example roomtemperature. The bed temperature is then increased and an operatorvisually observes the powder on the bed for certain visual cues thatindicate the onset of fusion, or that indicate that fusion is imminent.For example the color of the powder and the texture of the powder mayshift, indicating that the layer of powder is beginning to fuse. Whenthese visual cues are observed, the operator notes the temperature ofthe bed. The bed temperature setpoint for the lot being visually testedis typically between five to eleven degrees Celsius below thetemperature at which the layer of powder begins to fuse.

A disadvantage of the above described observation method is that itrelies of the visual acuity of the operator conducting the calibration.As a result, and due to differences between different operators, anoperator may select a bed temperature set point that is too high or toolow.

Another disadvantage of this method is that certain environmentalfactors, for example the type and intensity of lighting proximate to thebed may also affect the visual observations made by the operator. It hasbeen found that the structural properties for sintered powders can bestatistically affected by shifts of as little as a single degreeCelsius.

It is an object of the present invention to overcome these disadvantagesand other disadvantages associated with the prior art.

SUMMARY

It is an object of the present invention to provide method and systemfor analytically determining the bed temperature set point in a SLSmachine which avoids the problems associated with the known systems andmethods.

These and other objects of the present invention are achieved byprovision of a method for determining a bed temperature setpoint for usewith a powder in a selective laser sintering machine. The methodincludes the steps of providing a powder comprising a polymer for use ina selective laser sintering machine. The method further includes thestep of determining a ratio of a liquid portion of the powder to a solidportion of the powder as a function of temperature within a temperaturerange. The method further includes the step of selecting a bedtemperature setpoint in the temperature range corresponding to a desiredratio of the liquid portion of the powder to the solid portion of thepowder.

In yet other embodiments of the present invention, the method includesthe step of providing a selective laser sintering machine having a bedwith a variable temperature control. The method further includes thestep of setting a temperature of the bed to the selected bed temperaturesetpoint. The method further includes the step of building a part fromthe powder using the selective laser sintering machine.

In further embodiments of the present invention, the method includes thestep of determining a melt curve for the powder in the temperaturerange. The melt curve represents the energy required to increase thetemperature of the powder in the temperature range.

In yet a further embodiment of the present invention the method includesthe step of using differential scanning calorimetry to determine themelt curve for the powder.

In yet a further embodiment of the present invention, the methodincludes the step of determining the ratio of the liquid portion of thepowder to the solid portion of the powder as a function of temperaturebased on the melt curve.

In yet another embodiment of the present invention, the method includesthe step of selecting the desired ratio by referencing a librarycomprising data associated with a plurality of parts made using astandard powder with a selective laser sintering machine, each said partbeing made using a different bed temperature setpoint, each bedtemperature setpoint corresponding to a different ratio of a liquidportion of the powder to a solid portion of the powder. In yet a furtherembodiment of the present invention, the standard powder comprises apolymer, and the standard powder is different than the powder for whichthe desired ratio is being selected.

In yet a further embodiment of the present invention, the librarycomprises accuracy data corresponding to an accuracy of the partrelative to a design used to make the part. In yet a further embodimentof the present invention, the library comprises removal datacorresponding to the ease or difficulty of removing the part from apowder cake surrounding the part.

In yet another aspect of the present invention the powder comprising oneor more of polyetheretherketone (“PEEK”), polyetherketone ketone(“PEKK”), polyetherketone (“PEK”), polyetheretherketoneketone (“PEEKK”),or polyetherketoneetherketoneketone (“PEKEKK”). In some embodiments ofthe present invention, the powder comprises PEKK. In yet furtherembodiments of the present invention, the powder comprises recycledPEKK. In yet further embodiments, the powder comprises virgin PEKK.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an SLS machine in accordance with one embodiment ofthe present invention.

FIG. 2 illustrates a melt curve for a polymer powder for use in an SLSmachine in accordance with one embodiment of the present invention.

FIG. 3 illustrates a method in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

The inventors have discovered new methods and systems to overcome theproblems associated with the prior art. Specifically, the inventors havediscovered a method and system to define the bed temperature setpointfor a specific lot of powder. By employing analytical methods andsystems to each lot of powder, and, in some cases, to each run of theSLS machine, it is possible to determine a more accurate bed temperaturesetpoint resulting in builds having more structural similarity andbuilds that have desired build properties.

In some embodiments of the present invention, the detailed meltingbehavior of a specific lot of powder is determined. Based on the resultsof this determination, the bed temperature setpoint is established.

In one embodiment of the present invention, a melt curve is determinedfor a lot of powder to be used in an SLS machine. Such a melt curve maybe created, for example, by using differential scanning calorimetry(“DSC”). DSC is a thermoanalytical technique in which the difference inthe amount of heat required to increase the temperature of a sample andreference is measured as a function of temperature. Both the sample andreference are maintained at nearly the same temperature throughout theanalysis. In this way, it is possible to measure the amount of heatrequired to increase the temperature of the sample. Typically,differential scanning calorimetry is performed using a differentialscanning calorimeter. DSC units are sold under the brand names LinseisThermal Analysis, Mettler Toledo, Netzsch, Shimadzu, PerkinElmer,Setaram Instrumentation, and TA Instruments, among others.

In reference to FIG. 1, an SLS machine 10 in accordance with the presentinvention is illustrated. The system 10 includes a first chamber 20having an actuatable piston 24 disposed therein. A bed 22 is disposed atan end of the piston 24. The temperature of the bed 22 can be variablycontrolled via a controller 60 in communication with heating elements inand or around the bed 22. The bed temperature setpoint is input throughan interface 62 into the controller 60. Software executing on thecontroller 60 transmits a signal to one or more heating elements heatthe bed at or around the temperature setpoint. A second chamber 30 isadjacent to the first chamber 20. The second chamber 30 includes andincludes a table surface 32 disposed on an end of a piston disposedtherein. A powder 36 for use during in the SLS machine 10 is stored inthe second chamber 30 prior to the sintering step.

During operation of the SLS machine 10, a spreader 40 translates acrossa top surface of the first chamber 20, evenly distributing a layer ofpowder 36 across either the top surface of the bed 22, or the materialpreviously disposed on the bed. The SLS machine 10 preheats the powdermaterial 26 disposed on the bed to a temperature proximate to a meltingpoint of the powder. Preheating is typically accomplished by heating theactual bed, as described above, which transfers energy to the powder inthe form of heat via thermal conduction. Preheating the powder makes iteasier for the laser to raise the temperature of powder to a fusingpoint. In some embodiments of the present invention, there are alsoheating element in or around the second chamber in order to heat thepowder prior to deliver to the sintering surface.

A laser 50 and a scanning device 54 are disposed above the bed. Thelaser transmits a beam 52 to the scanner 54, which then distributes alaser beam 56 across the layer of powder 36 disposed on the bed 22 inaccordance with a build program. The laser selectively fuses powderedmaterial by scanning cross-sections generated from a three dimensionaldigital description of the part on the surface of bed having a layer ofthe powdered material disposed thereon. The laser 50 and the scanner 54are in communication with the controller 60. After a cross-section isscanned, the bed 22 is lowered by one layer thickness, a new layer ofpowdered material is disposed on the bed via the spreader 40, and thebed is rescanned by the laser. This process is repeated until the build28 is completed. During this process, the cylinder 34 in the secondchamber is incrementally raised to ensure that there is sufficientsupply of powder.

DSC analysis is specifically useful, for example, in determining thermaltransitions of polymers. In reference to FIG. 1, an optionaldifferential scanning calorimeter 64 is shown in communication with thecontroller 60. By analyzing the powder for use in the SLS process usingdifferential scanning calorimetry techniques, it is possible toanalytically determine the bed temperature to achieve desired buildproperties. The DSC is shown in FIG. 1 in communication with thecontroller, however, a person of ordinary skill in the art and familiarwith this disclosure will understand that there are many differentconfigurations that can be implemented to practice the presentinvention. For example, the DSC may not be connected to the controllerand a library of bed temperature setpoint is stored in the controller,and software executing on the controller determines a bed temperaturesetpoint based on the parameters of the type of powder being used in themachine.

In reference to FIG. 2, a chart 200 illustrating a melt curve 220 for asample of 60/40 PEKK is shown. The melt curve 220 was created using aDSC device. The melt curve shows heat flow 208 versus temperature 206for the 60/40 PEKK sample. The melt curve 220 illustrates the transitionof the PEKK sample from a powder to a liquid during a temperature range.As the temperature increases the powder begins melting and finallybecomes a liquid. Thus, during the illustrated range a portion of thepowder is a solid and a portion of the powder is liquid. The thermaltransition is illustrated in the DSC melt curve 220 by the peak areas inthe melt curve 100. These peak curves are indicative of the fact thatthe polymer requires additional heat during this thermal transitionperiod to increase its temperature relative to the standard employed inthe DSC analysis. In determining a bed temperature setpoint using theDSC analysis, the operator typically selects a point on the curve 220during the melt transition.

Superimposed on the melt curve 200 shown in FIG. 2 is a second curve 230representing a ratio of a liquid portion of the powder to a solidportion of the powder as a function of temperature within thetemperature range. The second curve 230 is based on the integration,i.e. the area under the curve, of the melt curve 220. Using this ratio130 it is possible to select a bed temperature setpoint in thetemperature range corresponding to a desired ratio of the liquid portionof the powder to the solid portion of the powder

For example, FIG. 2 illustrates three points on the curve 230: 25% ofthe sample melted 212, 50% of the sample melted 214, and 75% of thesample melted 216. These points correspond to three differenttemperatures: T₂₅, T₅₀, and T₇₅. Thus at temperature T₂₅, 25% of thesample has melted. It should be understood that the references pointsare included on the chart shown in FIG. 2 for reference only, and thatother melt percentages can be used.

It should be understood that within this thermal transition, there is arange of temperatures which the operator can select for the bedtemperature setpoint. The selected temperature will affect the buildproperties during the SLS process. For example, a low temperature withinthe thermal transition range typically results in built part that iseasier to remove from the cake bed. This is because there is relativelyless melting of the powder prior fusing by the laser, thus areasadjacent to the sintered powder are less likely to stick together andadhere to the built part. Therefore, it is easier for the operator toremove the built part from the unfused powder in the cake bed.

Although a lower bed temperature setpoint may result in increased easeof part removal, it may also result in less accuracy in the part built.Thus, if a more accurate build is desired, the operator can increase thebed temperature setpoint, resulting in a built part with less deviationfrom the specified dimensions thereof. Such built parts, however,typically are more difficult to remove from the cake bed because theparticles adjacent to the material sintered during the SLS process aremore tightly adhered thereto, requiring additional effort to removethem.

In determining the bed temperature setpoint, the properties of the builtpart are considered. If, for example, in an application in whichmanufacturing efficiency is desired and part accuracy is less important,the operator may select a lower bed temperature setpoint within thethermal transition area. If however, greater part accuracy is desired,the operator can select a higher bed temperature setpoint within thethermal transition area. IT should be understood that the bedtemperature may affect a multitude of parameters in the built part, andit is not limited to those expressly described herein.

Using the DSC analysis, it is possible for an operator to consistentlyselect the correct bed temperature setpoint for a specific lot of powderof a sample to achieve the desired build properties. Typically, thebuild properties are referenced against the percentage of the samplethat is melted. For example, it may be known that T₅₀ provides a partwith certain build properties. This data is initially derived for aspecific type of powder during a calibration process, which is describedbelow. After the calibration data is known, an operator may apply thecalibration data to a DSC analysis of a specific lot of powder todetermine the correct bed temperature setpoint to achieve the desiredbuild properties for that specific lot of powder (disclosed furtherbelow).

In reference to FIG. 3, a method in accordance with one embodiment ofthe present invention is illustrated. The method includes the steps ofproviding a powder comprising a polymer for use in a selective lasersintering machine 502. The method further includes the step ofdetermining a ratio of a liquid portion of the powder to a solid portionof the powder as a function of temperature within a temperature range506. The method further includes the step of selecting a bed temperaturesetpoint in the temperature range corresponding to a desired ratio ofthe liquid portion of the powder to the solid portion of the powder 508.The method further includes the step of setting the temperature of thebed to the selected bed temperature set point 510.

Calibration Process

Using the melt curve and ratio curve it is possible to determine a bedtemperature setpoint for a specific lot of powder. The first step is toconduct a calibration process. The calibration process allows theoperator identify at what point on the integration curve 130 a bedtemperature setpoint will achieve certain desired build properties. Oncethe calibration data is known, it can be applied to a DSC analysis of aspecific lot of powder to determine the correct bed temperature setpointto achieve the desired build properties with that specific lot ofpowder. It should be understood that this calibration process is ininitial step and does not require repeating for subsequent lots ofpowder. In some embodiments, calibration data of a first type of powderand can be used with a second type of powder to determine a bedtemperature setpoint. It should also be understood that this calibrationdata may be created by a third party, for example a vendor, and be madeavailable to a person operating an SLS machine. It should further beunderstood that the calibration step is used to aid in selection of abed temperature setpoint that will result in a built part having certainbuild properties, but that it is not necessary to perform thiscalibration process.

The operator may begin the calibration process by selecting a specificpolymer, for example 60/40 PEKK, and conducting a DSC analysis on a lotthereof to obtain data similar to that illustrated in the chart shown inFIG. 2. The operator then performs an SLS build using the powder in thetested lot. For the SLS build, the operator selects a bed temperaturesetpoint corresponding to a specific point on the ratio curve 230. Forexample, the operator may initially begin by selecting the 50% point 214on the integration curve. The 50% point 214 on the integration curvecorresponds to a temperature T₅₀. The operator conducts the SLS buildusing the lot of powder on which the DSC analysis was performed at a bedtemperature setpoint T₅₀.

After the part is built, the operator removes the built part from thepowder cake. In removing the part, the operator records the ease ordifficulty or removing the part from the cake and associates this datawith the ratio associated with 50% point 214. The operator then measuresthe accuracy of the built part and further associates this buildaccuracy data with the 50% point 214. The build accuracy can be measuredby conducting a visual comparison between the built part and a standardpart, for example, a drawing or a previously authenticated threedimensional part. In other embodiments, the accuracy of the built partcan be measured by using one or more cameras to capture a threedimensional image of the built part. Data of this captured image can becompared to an original design using, for example, software executing ona computer. In this manner, the operator can determine the relativeaccuracy of built part at a bed temperature of T₅₀. In addition, theoperator may measure any number of additional properties of the builtpart, including strength, ductility, fatigue, facture toughness,hardness, conductivity, tensile strength, etc.

The calibration process continues by performing SLS builds using bedtemperature setpoints associated with points up and down the ratio curve130. For each point, a bed temperature setpoint T_(XX) is determined andan SLS build is conducted. The properties of each build are recorded andassociated with the specific point on the integration curve. In thisway, it is possible to build a library or database comprising aplurality of points along the integration curve and having buildproperties associated with each point. This calibration data can then beapplied to DSC analysis performed on individual lots of powder, asfurther discussed below, to determine the correct bed temperaturesetpoint for that specific lot of powder and to achieve the desiredbuild properties.

Typically, the operator will perform this calibration process on a typeof powder, for example, 60/40 PEKK. After the calibration step isperformed, the results of the calibration process can be used ondifferent lots of that type of powder to determine the bed temperaturesetpoint that will achieve the desired results for that type of powder.It should also be understood that although a calibration process isdisclosed it is not necessary to perform this calibration step. Forexample, an operator may desire to conduct SLS builds at a bedtemperature setpoint in which 50% of the material is melted, regardlessof the result build properties. Therefore, it is not necessary to builda library of different values. The operator can simply proceed, asfurther discussed below, to conduct a DSC analysis on a specific lot ofpowder and determine the correct bed temperature setpoint therefrom.

Determining Bed Temperature Setpoint

After the calibration data is obtained for a specific type of powder,for example 60/40 PEKK, the operator can apply this data to DSC analysesof specific lots of the 60/40 PEKK powder to determine the correct bedtemperature setpoint to achieve the desired build properties for the60/40 PEKK blend. It is also possible to apply the calibration data forthe 60/40 blend to other types of polymers, and blends thereof, todetermine the correct bed temperature setpoint.

In one example, the operator seeks to build parts from a lot of 60/40PEKK powder. The operator first conducts a DSC analysis on a portion ofthe powder from that lot. The operator then determines the specificbuild properties that she desires in the parts to be built. Based on thedesired build properties, the operator references the calibration dataand determines what point on the integration curve, i.e. what percentageof melted material, will achieve the desired build properties. After theoperator determines that specific point on the integration curve, forexample YY, the operator references the DSC data for the specific lot of60/40 powder and determines the temperature T_(YY) associated with thepoint YY. T_(YY) is thus the bed temperature setpoint that should beused with the specific lot of 60/40 powder to achieve the desired buildproperties.

As discussed above, in some embodiments of the present invention, it isnot necessary to use calibration data. For example, it may be desired toconduct and SLS build with a layer of powder being 40% melted. In thisscenario, a DSC analysis is conducted on the specific lot of powder.Based on this data, the operator determines the temperature T₄₀associated with the point at which 40% of the powder is melted. This isthe bed temperature setpoint that the operator will run the SLS machinefor the build. If, for example, it is desired to build using a differentlot of 60/40 PEKK powder, a DSC analysis of that subsequent lot isperformed and a new T₄₀ is determined. This is particularly useful whenworking with new blends of powder, powders having several types ofdifferent powders, powders including additives, and recycled powderblends. In such cases, the melting point of the powders, and result bedtemperature setpoint, can vary. By using the method in accordance withthe present invention, it is possible analytically determine the correcttemperature.

In some embodiments of the present invention, a computer is incommunication with the SLS machine, for example, a controller associatedwith the SLS machine. The controller may further include calibrationdata associated therewith. During a build using the SLS machine anoperator may input certain parameters into the build machine, forexample the build properties, the specific type of powder, and DSC dataregarding the specific type of powder. Software executing on thecomputer determines a bed temperature setpoint based on the data inputinto the controller and sets the bed temperature thereto. In yet furtherembodiments of the present invention, the SLS machine includes a DSCdevice associated therewith. The DSC device performs periodic analysison the powder being used by the SLS machine and periodically adjusts thebed temperature based on the results of the analysis, the desired buildproperties, and the type of powder, among other possible variables.

Although the invention has been described with reference to a particulararrangement of parts, features and the like, these are not intended toexhaust all possible arrangements or features, and indeed many othermodifications and variations will be ascertainable to those of skill inthe art.

What is claimed is:
 1. A method for determining a bed temperaturesetpoint for use with a powder in a selective laser sintering machine,comprising the steps of: providing a powder comprising a polymer for usein a selective laser sintering machine; determining a melt curve for thepowder in a temperature range between a temperature when the powder is asolid and a temperature when the powder is a liquid, the melt curverepresenting the energy required to increase the temperature of thepowder in the temperature range using differential scanning calorimetry;selecting a point on the melt curve at which the sample has a desiredratio of a liquid portion of the powder to a solid portion of thepowder; selecting a bed temperature setpoint in the temperature range byselecting the temperature that corresponds to the selected point on themelt curve.
 2. The method of claim 1, further comprising the step of:selecting the point by referencing a library comprising data associatedwith a plurality of parts made using a standard powder with a selectivelaser sintering machine.
 3. The method of claim 1, wherein the powdercomprises polyetheretherketone (“PEEK”), polyetherketone ketone(“PEKK”), polyetherketone (“PEK”), polyetheretherketoneketone (“PEEKK”),or polyetherketoneetherketoneketone (“PEKEKK”).
 4. The method of claim3, wherein the powder comprises PEKK.
 5. The method of claim 4, whereinthe powder comprises a filler.
 6. The method of claim 5, wherein thefiller comprises carbon fiber.
 7. The method of claim 6, wherein thepowder comprises virgin PEKK.
 8. The method of claim 7, wherein thepowder comprises first recycle PEKK.
 9. The method of claim 8, whereinthe powder comprises second recycle PEKK.
 10. The method of claim 1,further comprising the step of: selecting the point by referencing alibrary comprising data associated with a plurality of parts made usinga powder having as similar composition to the provided powder with aselective laser sintering machine.
 11. A method for printing a componentfrom a polymer powder using a selective laser sintering machine,comprising the steps of: providing a selective laser sintering machinehaving a heating control system for providing an adjustable bedtemperature; providing a powder comprising a polymer for use in theselective laser sintering machine; determining a bed temperaturesetpoint for use with the powder in the selective laser sinteringmachine according to the following steps: determining a melt curve forthe powder in a temperature range between a temperature when the powderis a solid and a temperature when the powder is a liquid, the melt curverepresenting the energy required to increase the temperature of thepowder in the temperature range using differential scanning calorimetry;selecting a point on the melt curve at which the sample has a desiredratio of a liquid portion of the powder to a solid portion of thepowder; selecting a bed temperature setpoint in the temperature range byselecting the temperature that corresponds to the selected point on themelt curve; setting the heating control system in the selective lasersintering machine to the determined bed temperature setpoint for thepowder; printing a component from the powder using the selective lasersinter machine.
 12. The method of claim 11, further comprising the stepof: selecting the point by referencing a library comprising dataassociated with a plurality of parts made using a powder having assimilar composition to the provided powder with a selective lasersintering machine.
 13. The method of claim 11, wherein the powdercomprises polyetheretherketone (“PEEK”), polyetherketone ketone(“PEKK”), polyetherketone (“PEK”), polyetheretherketoneketone (“PEEKK”),or polyetherketoneetherketoneketone (“PEKEKK”).
 14. The method of claim13, wherein the powder comprises PEKK.
 15. The method of claim 14,wherein the powder comprises a filler.
 16. The method of claim 15,wherein the filler comprises carbon fiber.
 17. The method of claim 16,wherein the powder comprises virgin PEKK.
 18. The method of claim 17,wherein the powder comprises first recycle PEKK.
 19. The method of claim18, wherein the powder comprises second recycle PEKK.
 20. The method ofclaim 11, further comprising the step of: selecting the point byreferencing a library comprising data associated with a plurality ofparts made using a standard powder with a selective laser sinteringmachine.